In recent years, the processing of poultry has been automated so that most of the evisceration and cut-up steps are formed by mechanical devices. This has dramatically increased the speed and efficiency of poultry processing and has thus provided the consuming public with high quality poultry products at more reasonable prices.
Most of the modem poultry processing equipment is designed for use along suspended conveyor systems having a series of equally spaced depending shackles from which poultry carcasses are suspended upside down by their legs and conveyed along a processing path. Various processing machines are disposed along the processing path for operating upon the suspended carcasses progressively as they move along the path, to prepare the poultry for public sale and consumption.
A typical poultry processing line might include, for example, a vent cutter, a bird opener, an eviscerator, a neck breaker, a lung puller, and a crop remover. In addition, such processing lines might include machines for subdividing the poultry carcasses into their various commonly consumed pieces, such as breasts, backs, wings, legs and thighs.
The step of separating the poultry thigh from the back portion of the carcass is difficult to perform uniformly from bird to bird and without damaging the bone of the joint where the thigh is separated from the back portion. The muscles and tendons adjacent the joint are difficult to reach with automated cutting implements and there is a hazard that the cutting implements will chip, crack or splinter the bones as they make the cuts between the bones of the joints, leaving potentially harmful bone chips in the edible product.
As disclosed in U.S. Pat. 5,188,559 issued Feb. 23, 1993, automated machines are available for separating the thighs from the back portions of birds as birds are suspended upside down by their legs and moved in sequence along a processing path. While the machines have been largely successful, there are occasions when the birds are not properly aligned as they pass through the initial cutting blades for initially cutting the tissue that holds the bones of the joints together at the thigh and the back portion of the carcass. The tissue surrounding the bones of the joint of the thigh and back must be progressively cut to open the joint, and once the joint is open, it is desirable to rotate the back portion of the bird with respect to the thighs so as to twist the socket of the back portion away from the thigh bones, while cutting the tissue that connects the thighs to the back portion. It is highly desirable that more of the meat be left on the thighs than on the back portion, since the thighs are much more valuable than the back portions. Also, it is desirable to make a perfect cut about the thigh bones after the back portions have been rotated to pull the thighs from their sockets so that the appearance of the meat clinging to the thighs is not degraded during the cutting and removing procedures.
An important aspect of achieving the perfect cut between the thigh and the back portion is control of the position of the bird as the bird progresses through the cutting and removal procedures.
Accordingly, it would be desirable to provide an improved method and apparatus for more accurately guiding the poultry carcass to the cutters which cut through the tissue extending between the thighs and the back portions of the carcasses, and then to firmly grasp and pull the back portion of the carcass away from the thighs with a tumbling movement of the back portion so as to rotate the back portion with respect to the proximal end of the thigh bone, causing the back portion to progressively separate from the thighs and allowing the meat which can be pulled by the thighs from the back portion to remain with the thighs, thereby enhancing the weight and value of the thighs. It is to the provision of such a method and apparatus that the present invention is primarily directed.